On April 16th my marine
ecology class took our third field trip and this time it was out to Bodega Head
in Bodega Bay, CA. It was an absolutely gorgeous day in Bodega with clear sky’s
and the sun shining bright so we all had a great time. When we first walked
down to the beach I noticed that there was an extremely large number of
by-the-wind sailor’s that had been washed up on the shore. I had seen the same
species on the shore of Horseshoe Cove which is very close to Bodega Head but
this was at least 100 times the number I had seen 2 weeks prior. At first I was
confused because the wind was not even very strong so I was wondering why so
many had been blown in and how many could possibly be still out there so I
thought I would do some research into this species.
The by-the-wind sailor’s are a
species of hydrozoa called Velella
velella and are related to the Portuguese man-of-war. This species in
particular however does not have a strong enough sting to be felt by human
touch. These Hydrozoa enjoy warmer waters so with the current warmer than
average temperatures off the coast, they are thriving and moving in closer to
the shore. With gentle winds the Velella
velella tend to use their sail direction to move 45 degrees to the
direction of the wind and keep them out at see but when the winds are too
strong they loose control. Strong surface winds cause them to spin out of
control and follow the path of the wind, which sends them, sailing into the shore.
Apart from
all of the unique animals that I found when searching through the intertidal
and the mudflats I also found some marine plant life that really interested me.
While walking on the shore of Duncan’s Landing, I found a piece of algae that
appeared to be some type of macroalgae with another smaller algae attached to
it’s large blade. After asking my professor, Dr. Shannon Lee, I found out that
the large blade was a type of red algae known as Chondracanthus exasperatus, which is more commonly known as Turkish
Towel. This type of macroalgae has a range that stretches from Baja California
up the west coast of North America to Alaska. The color of the specie varies
but above Point Conception in California, it is mostly brick red such as the
one I discovered. As for the smaller algae that was growing off of the red algae;
that required some more investigative work. After doing some research of red
algae online I was able to narrow the smaller algae genus to Plocamium after determining it was apart
of the division Rhodophyta. There are about 40 species of Plocamium so without further testing I could not determine exactly
which species it is.
It would be
very interesting to be able to study the two algae and determine which type of
symbiotic relationship they have. Since I only found the two species attached on
the shore I cannot say weather it is mutualism, communalism, or parasitism
without seeing how they behave in their environment but I would really like to
know.
References
http://www.mercurynews.com/central-coast/ci_27973071/wind-carries-blue-velella-onto-monterey-bay-beaches
http://seagrant.oregonstate.edu/sgpubs/onlinepubs/g03004.pdf
http://www.weather.com/science/nature/news/velella-jellyfish-west-coast-wind
http://www.mbari.org/staff/conn/botany/reds/devon/home.htm
http://www.seasonsinthesea.com/mar/kelp.shtml
http://www.mbari.org/staff/conn/botany/reds/eric/PHYS.HTM
http://www.algaebase.org/search/species/detail/?species_id=4937
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